Neurilemoma of the popliteal fossa: report of two cases with long subclinical course and misleading presentation.

The authors report two cases of neurilemoma localised in the popliteal fossa. Both patients experienced non-specific symptoms, such as painful numbness and burning dysaesthesia, involving the lower extremity. Tinel's sign was positive over the popliteal fossa. The patients sought medical advice and underwent conservative treatment without any relief, for a long time before the right diagnosis was made. Magnetic resonance imaging revealed in both patients a well- circumscribed mass posterior to the sciatic nerve, occupying the popliteal fossa. Following surgical excision of the neurilemoma, the patients experienced immediate relief of their chronic symptoms. In similar situations, ultrasound or magnetic resonance imaging of the whole sciatic nerve should be performed if this is indicated by detailed physical examination. Once the diagnosis is made, neurilemomas should be surgically removed, in order to exclude malignancy, prevent neurologic deficits and provide relief of symptoms.